Hello! I'm trying to replace the circuitry of a 606 Roland kickdrum that has a pair of resistors tied to ground that determine the Pitch.
I want to Voltage control that resistance. To do so, I can’t use OTA (as LM13700) as single ended resistors ( I wouldn't be able to reach very low resistance values).
I’m trying N-channel JFET (using a J109 at the moment. it has a very low Rds of 12 Ohm).
I'm tweaking with a part of Ray Wilson's schematic. the VCr section is this:
The problem i face is that the negative half of the resulting waveform is heavily distorted.
From what i I read, Mosfet as VCR should be used mainly for Control Voltage and not in audio Path because they introduce harmonic distorsion but I don’t think this is the real issue in this case.
What am I doing wrong?
I want to Voltage control that resistance. To do so, I can’t use OTA (as LM13700) as single ended resistors ( I wouldn't be able to reach very low resistance values).
I’m trying N-channel JFET (using a J109 at the moment. it has a very low Rds of 12 Ohm).
I'm tweaking with a part of Ray Wilson's schematic. the VCr section is this:
The problem i face is that the negative half of the resulting waveform is heavily distorted.
From what i I read, Mosfet as VCR should be used mainly for Control Voltage and not in audio Path because they introduce harmonic distorsion but I don’t think this is the real issue in this case.
What am I doing wrong?